# pass
name = input('输入名字')

if name == 'zb':
    print('hello zhoubiao')
elif name == 'wd':
    pass
else:
    print('你好 ', name)

# del
# del 删除的是名称而不是值
x = 1
print(x)
del x
a = [1, 2]
b = a
del a
print(b)

# exec
# exec 将字符串作为代码执行
exec("print(123456)")
# eval
# eval 计算字符串代表的值
print(eval('1+1*2*3-2'))

